echomessage.java

High performance DB query

/*
 * @(#)$Id: EchoMessage.java,v 1.7 2004/07/02 23:59:22 huebsch Exp $
 *
 * Copyright (c) 2001-2004 Regents of the University of California.
 * All rights reserved.
 *
 * This file is distributed under the terms in the attached BERKELEY-LICENSE
 * file. If you do not find these files, copies can be found by writing to:
 * Computer Science Division, Database Group, Universite of California,
 * 617 Soda Hall #1776, Berkeley, CA 94720-1776. Attention: Berkeley License
 *
 * Copyright (c) 2003-2004 Intel Corporation. All rights reserved.
 *
 * This file is distributed under the terms in the attached INTEL-LICENSE file.
 * If you do not find these files, copies can be found by writing to:
 * Intel Research Berkeley, 2150 Shattuck Avenue, Suite 1300,
 * Berkeley, CA, 94704.  Attention:  Intel License Inquiry.
 */


package util.network.ping;

import services.network.Payload;
import util.FreeList;
import util.FreeListFactory;
import util.network.serialization.GenericByteBuffer;
import util.network.serialization.SerializationManager;

/**
 * Class EchoMessage
 *
 */
public class EchoMessage implements Payload {

    public static long serialVersionUID =
        SerializationManager.getSerialUID("util.network.ping.EchoMessage");
    public static final byte ECHO_MESSAGE = 8;
    public static final byte ECHOREPLY_MESSAGE = 0;
    private byte type;
    private int identifier;
    private int sequenceNumber;
    private double sendTime;
    private Payload data;
    private int size;
    private static FreeList freeList = new FreeList(new EchoMessageFactory());

    /**
     * Constructor EchoMessage
     */
    protected EchoMessage() {}

    /**
     * DeSerialize the object from the provided GenericByteBuffer.
     *
     * @param inputBuffer
     */
    public EchoMessage(GenericByteBuffer inputBuffer) {
        byte type = inputBuffer.get();

        this.init(inputBuffer.getInt(), inputBuffer.getInt(),
                  inputBuffer.getDouble(),
                  SerializationManager.deSerialize(inputBuffer));

        this.type = type;
    }

    /**
     * Serialize the object into the provided GenericByteBuffer.
     *
     * @param outputBuffer
     * @return
     */
    public long serialize(GenericByteBuffer outputBuffer) {
        outputBuffer.put(type);
        outputBuffer.putInt(identifier);
        outputBuffer.putInt(sequenceNumber);
        outputBuffer.putDouble(sendTime);
        SerializationManager.serialize(outputBuffer, data);

        return serialVersionUID;
    }

    /**
     * Method init
     *
     * @param identifier
     * @param sequenceNumber
     * @param sendTime
     * @param data
     */
    public void init(int identifier, int sequenceNumber, double sendTime,
                     Payload data) {
        this.type = ECHO_MESSAGE;
        this.identifier = identifier;
        this.sequenceNumber = sequenceNumber;
        this.sendTime = sendTime;
        this.data = data;

        if (data != null) {
            size = 8 + SerializationManager.getPayloadSize(data);
        } else {
            size = 8;
        }
    }

    /**
     * Method getSize
     * @return
     */
    public int getSize() {
        return size;
    }

    /**
     * Method getType
     * @return
     */
    public byte getType() {
        return type;
    }

    /**
     * Method convertToReply
     */
    public void convertToReply() {
        type = ECHOREPLY_MESSAGE;
    }

    /**
     * Method getIdentifier
     * @return
     */
    public int getIdentifier() {
        return identifier;
    }

    /**
     * Method getSequenceNumber
     * @return
     */
    public int getSequenceNumber() {
        return sequenceNumber;
    }

    /**
     * Method getSendTime
     * @return
     */
    public double getSendTime() {
        return sendTime;
    }

    /**
     * Method getData
     * @return
     */
    public Payload getData() {
        return data;
    }

    /**
     * Method allocate
     *
     * @param identifier
     * @param sequenceNumber
     * @param sendTime
     * @param data
     * @return
     */
    public static EchoMessage allocate(int identifier, int sequenceNumber,
                                       double sendTime, Payload data) {
        EchoMessage message = (EchoMessage) freeList.allocate();

        message.init(identifier, sequenceNumber, sendTime, data);

        return message;
    }

    /**
     * Method free
     *
     * @param message
     */
    public static void free(EchoMessage message) {
        freeList.free(message);
    }

    /**
     * Method toString
     * @return
     */
    public String toString() {
        return "<ECHOMESS TYPE:" + type + ", ID:" + identifier + ", SEQ:"
               + sequenceNumber + ", TIME:" + sendTime + ", DATA:" + data + ">";
    }
}


/**
 * Class EchoMessageFactory
 *
 */
class EchoMessageFactory implements FreeListFactory {

    /**
     * Method create
     * @return
     */
    public Object create() {
        return new EchoMessage();
    }
}